The present invention relates to a cooler arrangement for a vehicle engine.
The amount of air which can be supplied to a supercharged combustion engine depends on the pressure of the air but also on the temperature of the air. Supplying the largest possible amount of air to the combustion engine entails cooling the compressed air in a charge air cooler before it is led to the combustion engine. The charge air cooler is often fitted in front of the vehicle's ordinary radiator, where it is cooled by surrounding air. The compressed air can thus be cooled in the charge air cooler to a temperature substantially corresponding to the temperature of the surroundings. The charge air cooler is made with advantage of a material with good heat-conducting properties such as aluminium.
The technique called EGR (Exhaust Gas Recirculation) is a known way of leading part of the exhaust gases from a combustion process in a combustion engine back, via a return line, to an inlet line for supply of air to the combustion engine. Adding exhaust gases to the air leads to a lower combustion temperature, resulting inter alia in a reduced content of nitrogen oxides NOx in the exhaust gases. It is important that the returning exhaust gases are also subjected to good cooling so that they will not heat the air which is led to the combustion engine. The exhaust gases are therefore cooled in an EGR cooler before they are mixed with the air in the inlet line. As exhaust gases contain corrosive substances, the EGR cooler is with advantage made of a corrosion-resistant material such as stainless steel.
SE 527 869 refers to an air-cooled cooler device adapted to being fitted in front of the vehicle's ordinary radiator at a front portion of a vehicle. The cooler device comprises a charge air cooler and an EGR cooler which have a common outlet tank so that they constitute a composite tank unit. Such a cooler device may be made compact and occupy little space, while at the same time the compressed air and the exhaust gases can be mixed with one another substantially immediately after they have been cooled in the respective coolers.